Answer:
(A) 654.545 Kw
(B)
Explanation:
We have given resistance of the toaster
Resistance of nichrome heating element
Both the resistances are connected in series so same current will flow through the circuit
Potential difference across the toaster V = 120 volt
So current
(a) Power dissipated in toaster
(B) Power dissipated in heating element
Answer:
The force felt by charge 3 is F=(-5.6*10⁻⁶,3.36⁻⁵)N
Explanation:
As the superposition principle applies to static charges, we can find the net electric force as the sum of the two forces felt by q3.
Looking at the drawing and knowing that they form an equilateral triangle of lenght 4 we can conclude that each internal angle is 60°.
So, the positions in our coordinate system are:
Now using Coulomb's force:
Where d=4, q1 = -7.8*10⁻⁹C, q2 = -15.6 *10⁻⁹C, q3 = 8.0 *10⁻⁹C, k=8.98*10⁹, e0=8.8*10¹⁰:
Replacing we get 2 equations:
To work with the sam
F=∑F_i=3.5*10⁻⁴(0.023,0.032)+7*10⁻⁴(-0.016,0.032)=
=((3.5*10⁻⁴-7*10⁻⁴)*0.016,(3.5*10⁻⁴+7*10⁻⁴)*0.032)=
F=(-5.6*10⁻⁶,3.36⁻⁵)N
A) +5 J
B) +1 J
Explanation:
A)
The internal forces (interaction forces) acting on a system do not change the mechanical energy (sum of potential and kinetic energy) of the system.
However, these forces are responsible for converting the energy from one form into another; the work done by these forces is equal to the amount of energy converted from one form into the other.
In this problem, we have:
is the loss in potential energy of the system
is the gain in kinetic energy of the system
By looking at these numbers, this means that the internal forces have converted 5 J of energy from potential energy into kinetic energy (while the additional +1 J missing is due to external forces, as explained in part B).
Therefore, the work done by internal forces is
W = +5 J
B)
First of all, we calculate the change in mechanical energy of the system.
The mechanical energy of a system is the sum of its kinetic energy (K) and its potential energy (U):
So, the change in mechanical energy is equal to the sum of the changes of kinetic energy and the changes of potential energy:
In this problem:
So, the change in mechanical energy is:
According to the work-energy theorem, the work done by external forces on a system is equal to the change in mechanical energy of the system: therefore in this case, the work done by external forces is